Solar Electric System – Inverters

    Published: 06-16-2009
    Views: 7,935
    SolarWorld Authorized Installer Keith Knowles talks about the different types of solar inverters that are available and how to choose the best one for a particular home.

    Keith Knowles: Hi! I am Keith Knowles with LiveLight Energy. I am a licensed Solar Contractor and an authorized installer for SolarWorld, America's largest manufacturer of solar panels. I'm here today to talk to you about putting solar equipment on your home and helping you make the right choice.

    We're going to talk today about inverters. The inverter conditions the power from your solar panel, so that it can be used in your home or be put back on the grid for credit on your power bill. Since the inverter interacts with the utility grid, it's required by law to shut down whenever the power goes out.

    If you want your solar electric system to provide back up power, you'll need to include batteries and specialized electronics that comply with the electrical code. These extra components can add thousands of dollars to your system cost, so a few people so this. There are two basic types of inverters the first is the string inverter which requires six or more panels to operate. String inverters are the most cost effective inverters and are used in the majority of systems. Another type of inverter is the micro inverter which is gaining popularity because of its flexibility. Each inverter goes behind the one panel and it's a little bit more labor-intensive to install, but it helps for sheeting issues or systems that are on multi-pitched roofs.

    No matter what type of inverter you go with, look for a minimum 10 year warranty and UL listing. Inverter efficiency can also be important, so look for independent tests. A top of the line string inverter will be up, around 95% efficiency or micro inverters can be a little lower than that. Just like with solar panels, you also want to look for well-established manufactures with quality-driven production.

    You and your installer will need to make sure that the panels and inverters you choose will work well together. Most inverter manufactures make a variety of sizes. The size you get should typically be equal to or larger than the nominal output of your solar panels. Now you're ready to select the inverter that's right for your system.